Worth noting that paying by card offers some advantages to the business accepting the payment too - less cash to count at the end of the day, less cash on the premises that could be a target for theft, less cash to have to transport to a bank...etc which can make up for the small charge they have to pay on each transaction.

For small payments up to about ?10 we'll soon all be using 'contactless' cards (swipe like an Oyster) or mobile phones with similar 'contactless' chips inside them that only require a PIN to be entered occasionally (e.g. once for every ?50 spent). Payment terminals are currently being rolled out across London starting in Canary Wharf and the major train stations.

Not sure how I'll remember my PIN after ?50 worth of beer, though.